This application claims the priority of German Patent Document DE 199 50 505.5, filed Oct. 20, 1999, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a device for controlling the light distribution of a headlamp installation of a motor vehicle which has a first light source for an additional lamp and a second light source for a driving lamp.
In a method of this type for controlling the light distribution pattern of a headlamp installation according to German Patent Document DE 38 44 364 C2, in order to prevent a decrease in visibility of the driver of a vehicle where there is oncoming traffic, the vehicle""s own lane is illuminated with an elevated light level. To do this, a light sensor records various areas of the driver""s field of vision and the light level to illuminate the vehicle""s own lane is increased if a threshold from the light emissions from the area of the oncoming lane is exceeded. However, if the value for the light emissions from the area of the vehicle""s own lane or the value for light emissions in an area lying above the lanes drops below a threshold value, the light level is reduced again. To increase the light level, another headlamp is provided in addition to the low beams, which can be switched on additionally in the manner described above. Alternatively, a movable shutter is provided in a headlamp that is already present, with which the light distribution pattern can be changed. Instead of the movable shutter, the light source can also be moved so that the position of the point of highest light intensity is moved.
In contrast to this state of the art, a task of the invention is to produce an improved device for controlling the light distribution pattern of a headlamp arrangement in a motor vehicle.
According to the invention, this task is solved by providing a device for controlling the light distribution of a headlamp installation of a motor vehicle, which has a first light source for an additional lamp, and a second light source for a driving lamp, wherein the first light source is mounted so that it can swivel and, in a first position, illuminates areas lying on edges of a roadway on a vehicle""s own lane and, in a second position, illuminates the vehicle""s own lane. It is suggested that a light source for an additional lamp be mounted so that it can swivel. In this process, the light source for an additional lamp in a first position will illuminate parts of the vehicle""s own lane lying in the area of the edges of the lane, while in its second position it illuminates the vehicle""s own lane, preferably at a greater distance. In an advantageous manner, a headlamp arrangement is thus produced in which without a lot of construction effort, in addition to an additional lamp (e.g., to reduce the beam for opposing traffic), at the same time an additional high-beam headlamp (in this case the vehicle""s own lane will not be illuminated except at a great distance) or an expressway light (this is a light bundle with a bright-dark boundary that is sharp and basically horizontal which can easily be raised in relation to the low-beam light) can be implemented. In this process, the swiveling capability of the light source can be implemented in that the reflector is swivelled together with the light source or only the light source is swivelled, or only the reflector.
Advantageous further developments of the invention are described below and in the claims. It is suggested that the light source for the additional lamp be arranged in such a way that it has a common light emission area with at least one other light source. Advantageously, because of this measure, when the light source is switched on for an additional lamp, no new illuminated area will be produced that could distract or even irritate the oncoming traffic. For a common light emission area, for example, the light source for an additional lamp can be mounted in the area of the low-beam lamp or combined with a marker light (parking light).
The low-beam lamp and light source for an additional lamp and/or the marker light could be mounted, for example, in a common reflector. It is also contemplated to mount the light source for an additional lamp and the low-beam lamp under a common cover lens and to light up the area found around both light sources with the help of an additional lamp, e.g., the marker light, so that in spite of the separate light generation systems the pattern of a uniform headlamp is maintained.
Finally, it is planned that a control device will be provided to control the light source for an additional lamp, which turns on the light source for the additional lamp and also adjusts its position. On the input side, the control device has a comparator device which is connected with light sensors, e.g., for the area of an oncoming lane and the ambient light and if necessary other sensors, e.g., for vehicle speed. The light sensor basically records the visual field of a driver in driving direction and determines the light emissions for various areas of the field of vision. The comparator device compares the intensity of light emission for each area to a threshold value for each and generates a control signal for the additional lamp from the result of this comparison.
The additional lamp can also be used as a bad weather lamp, so that when there is a reflecting road surface, e.g., because of rain water, the illumination of the vehicle""s own lane is increased. A bad weather lamp of this type can be switched on manually using a special switch or automatically using a suitable sensor, e.g., a rain sensor.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.